Most plastic is made from the raw material crude oil. This is a fossil fuel, which we discussed earlier in the week, as being a finite resource.  For this reason, in recent years there has been a big push on recycling plastics and finding alternatives to use instead.

But do you know your polyethene from your PET? Try this activity and find out!

  1. Gather your plastic samples.
  2. Half fill a container with water and place sample 1 under the water before letting it go. Do the same for the rest of the samples. Observe and record which plastics float and which sink.
    Using the same samples (removed from the water) fold each piece of plastic backwards and forwards to see what happens – some plastics snap under pressure; others simply fold into a crease whilst some plastics show a white line called stress whitening.
  3. Record your results.
  4. Use this classification key to identify which type of plastic is which.

You could extend this activity by finding out about how scientists and engineers are helping to develop plastic waste recycling systems, for example: old plastic window frames can be cleaned, made into tiny pellets and melted to be reformed into new window and door frames or other products. Thanks to companies like INOVYN at Newton Aycliffe in England, PVC-U is no longer a single-use material and is much more sustainable. Nothing goes to waste and, more importantly, nothing is deliberately thrown away to find its way into drains, rivers and the ocean.

Don’t forget to send us your results at to be in with a chance of winning a prize!

Until next time, Keep calm and apply some Science!

This activity was taken from the downloadable resources found at  and was based on an activity from